Systems and methods of gap calibration via direct component contact in electronic device manufacturing systems

ABSTRACT

An electronic device manufacturing system includes a motion control system for calibrating a gap between surfaces of process chamber or loadlock components by moving those component surfaces into direct contact with each other. The component surfaces may include a surface of a substrate and/or a substrate support and a surface of process delivery apparatus, which may be, e.g., a pattern mask and/or a plasma or gas distribution assembly. The motion control system may include a motion controller, a software program executable by the motion controller, a network, one or more actuator drivers, a software program executable by the one or more actuator drivers, one or more actuators, and one or more feedback devices. Methods of calibrating a gap via direct contact of process chamber or loadlock component surfaces are also provided, as are other aspects.

FIELD

This disclosure relates to systems and methods of distributed motioncontrol of apparatus used to support and process substrates inelectronic device manufacturing systems.

BACKGROUND

An electronic device manufacturing system may include one or moreprocess chambers in which substrates are processed to fabricate thereonelectronic devices (e.g., integrated circuits and/or flat paneldisplays). The process chambers may be operated at a vacuum level(ranging from about, e.g., 0.01 Torr to about 80 Torr) and at hightemperatures (ranging from about, e.g., 100 degrees C. to 700 degreesC.). A same or different substrate process, such as, e.g., deposition,etching, annealing, curing, or the like of a film layer on a substrate,may take place in each process chamber of the electronic devicemanufacturing system. Substrate processing may also occur in a loadlockof some electronic device manufacturing systems. A loadlock is a chamberthrough which substrates are transferred between process chambers and afactory interface for transport elsewhere in an electronic devicemanufacturing system.

In a substrate process, one or more film layers of a desired materialhaving a desired thickness and uniformity may be selectively applied toor removed from a substrate via process delivery apparatus, such as,e.g., a pattern mask and/or a plasma or gas distribution assembly. Toensure that such desired thicknesses and uniformities are preciselyapplied or removed, a gap between a substrate and the process deliveryapparatus should be tightly controlled. However, as the size of processchambers increases to handle larger substrate sizes, larger batch loadsof substrates, and higher process temperatures (which may affect thethermal expansion of process components), the desired gap may becomemore difficult to control. Electronic device manufacturing systems maytherefore benefit from improved gap calibration systems and methods.

SUMMARY

According to a first aspect, a motion control system of an electronicdevice manufacturing system is provided. The motion control systemcomprises a motion controller comprising a programmable processor, amemory, and a gap calibration software program stored in the memory andexecutable by the programmable processor. The motion control system alsocomprises an actuator driver coupled to the motion controller andcomprising a driver software program. The motion control system furthercomprises an actuator coupled to the actuator driver and to a processdelivery apparatus or a substrate support located in a process chamberor loadlock, wherein the actuator is configured to move the processdelivery apparatus or the substrate support. The motion control systemstill further comprises a feedback device coupled to the actuator and tothe motion controller. The gap calibration software program isconfigured to cause direct contact between respective surfaces of theprocess delivery apparatus and the substrate support or a substratereceived on the substrate support.

According to a second aspect, an electronic device manufacturing systemis provided. The electronic device manufacturing system comprises atransfer chamber and a process chamber coupled to the transfer chamber,wherein the transfer chamber is configured to transfer one or moresubstrates to and from the process chamber, and the process chamber isconfigured to process the one or more substrates therein. The electronicdevice manufacturing system also comprises a loadlock coupled to thetransfer chamber, wherein the transfer chamber is configured to transferthe one or more substrates to and from the loadlock. The electronicdevice manufacturing system further comprises a motion controllercomprising a programmable processor, a memory, and a gap calibrationsoftware program stored in the memory and executable by the programmableprocessor. The gap calibration software program is configured to causedirect contact within the process chamber between respective surfaces ofprocess delivery apparatus and a substrate support or one of the one ormore substrates received on the substrate support.

According to a third aspect, a method of calibrating a gap betweencomponent surfaces in a process chamber or a loadlock of an electronicdevice manufacturing system is provided. The method comprises thefollowing: preparing for a gap calibration by issuing preparatoryinstructions from a motion controller to one or more actuator drivers;actuating one or more actuators in the process chamber or the loadlockto cause direct contact between the component surfaces without takingthe process chamber or the loadlock offline; and responding to detecteddirect contact between the component surfaces.

Still other aspects, features, and advantages in accordance with theseand other embodiments of the disclosure may be readily apparent from thefollowing detailed description, the appended claims, and theaccompanying drawings. Accordingly, the drawings and descriptions hereinare to be regarded as illustrative in nature, and not as restrictive.

BRIEF DESCRIPTION OF DRAWINGS

The drawings, described below, are for illustrative purposes only andare not necessarily drawn to scale. The drawings are not intended tolimit the scope of the disclosure in any way.

FIG. 1 illustrates a schematic top view of an electronic devicemanufacturing system according to embodiments of the disclosure.

FIGS. 2A-2E illustrate various schematic side views of process componentconfigurations according to embodiments of the disclosure.

FIG. 3 illustrates a schematic side view of a motion control systemaccording to embodiments of the disclosure.

FIG. 4 illustrates a flowchart of a method of calibrating a gap betweencomponent surfaces in a process chamber or a loadlock of an electronicdevice manufacturing system according to embodiments of the disclosure.

FIGS. 5A and 5B illustrate position and velocity software control loopsexecutable in an actuator driver according to embodiments of thedisclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to example embodiments of thedisclosure, which are illustrated in the accompanying drawings. Whereverpossible, the same reference numbers will be used throughout thedrawings to refer to the same or like parts.

Electronic device manufacturing systems in accordance with one or moreembodiments of the disclosure may include a distributed motion controlsystem configured to detect direct contact of moving process componentsinside a process chamber or a loadlock configured to process substrates.Direct contact detection by a motion controller executing a gapcalibration software program may be used to calibrate gap spacingbetween surfaces of process components. Calibrating and then tightlycontrolling gap spacing may advantageously improve film depositionand/or film etching properties including application and/or removal ofdesired thicknesses and uniformities. Tightly controlling gap spacingmay also advantageously affect the rate of film deposition and/oretching. When precisely controlled, gap spacing may further improvematching of process chamber performance in an electronic devicemanufacturing system with two or more process chambers. Desired gapspacing varies by application. For example, desired gap spacing foratomic layer deposition may vary between 4 mils and 80 mils for a gapbetween a chemical injector and a substrate, and desired gap spacing fora bevel etch may vary between 1 mil and 20 mils for a gap between apattern mask and a substrate.

The direct contact between process component surfaces during gapcalibration may include contact between any combination of thefollowing: a substrate surface, a substrate support surface, and/or aprocess delivery apparatus surface.

Further details of example embodiments illustrating and describing gapcalibration via direct contact of process component surfaces, as well asother aspects including methods of calibrating a gap between processcomponent surfaces in a process chamber or loadlock of an electronicdevice manufacturing system, will be explained in greater detail belowin connection with FIGS. 1-5B.

FIG. 1 illustrates an electronic device manufacturing system 100 inaccordance with one or more embodiments. Electronic device manufacturingsystem 100 may perform one or more processes on a substrate 102.Substrate 102 may be any suitably rigid, fixed-dimension, planararticle, such as, e.g., a silicon-containing disc or wafer, a patternedwafer, a glass plate, or the like, suitable for fabricating electronicdevices or circuit components thereon. In some embodiments, thesubstrate may be, e.g., a 200 mm, 300 mm or 450 mm diametersemiconductor wafer.

Electronic device manufacturing system 100 may include a process tool104 and a factory interface 106 coupled to process tool 104. Processtool 104 may include a housing 108 having a transfer chamber 110therein, and transfer chamber 110 may have a substrate transfer robot112 located therein. A plurality of process chambers 114, 116, and 118may be coupled to housing 108 and transfer chamber 110. A loadlock 120may also be coupled to housing 108 and transfer chamber 110. Transferchamber 110, process chambers 114, 116, and 118, and loadlock 120 may bemaintained at a vacuum level. The vacuum level for transfer chamber 110may range from about, e.g., 0.01 Torr to about 80 Torr. Other vacuumlevels may be used.

Transfer robot 112 may include multiple arms and one or more endeffectors that are configured to transfer substrates 102 to and from anyprocess chamber and loadlock physically coupled to transfer chamber 110(note that substrates 102 and substrate placement locations are shown inFIG. 1 as circles).

A same or different substrate process may take place in each of processchambers 114, 116, and 118, such as, e.g., atomic layer deposition(ALD), physical vapor deposition (PVD), chemical vapor deposition (CVD),etching, annealing, curing, pre-cleaning, metal or metal oxide removal,or the like, on one or more substrates. For example, a PVD process maytake place in one or both of process chambers 114, an etching processmay take place in one or both of process chambers 116, and an annealingprocess may take place in one or both of process chambers 118. Otherprocesses may be carried out on substrates therein.

Loadlock 120 may be configured to interface with, and be coupled to,transfer chamber 110 on one side and factory interface 106 on anopposite side. Loadlock 120 may have an environmentally-controlledatmosphere that may be changed from a vacuum environment (whereinsubstrates may be transferred to and from transfer chamber 110) to an ator near atmospheric-pressure inert-gas environment (wherein substratesmay be transferred to and from factory interface 106). In someembodiments, loadlock 120 may be a stacked loadlock having a pair ofupper interior chambers and a pair of lower interior chambers that arelocated at different vertical levels (e.g., one above another). In someembodiments, the pair of upper interior chambers may be configured toreceive processed substrates from transfer chamber 110 for removal fromprocess tool 104, while the pair of lower interior chambers may beconfigured to receive substrates from factory interface 106 forprocessing in process tool 104. In some embodiments, loadlock 120 may beconfigured to perform a substrate process (e.g., an etch or a pre-clean)on one or more substrates 102 received therein.

Factory interface 106 may be any suitable enclosure, such as, e.g., anEquipment Front End Module or EFEM. Factory interface 106 may beconfigured to receive substrates 102 from substrate carriers 122 (whichmay be, e.g., Front Opening Unified Pods or FOUPs) docked at variousload ports 124 of factory interface 106. A factory interface robot 126(shown dotted) may be used to transfer substrates 102 between substratecarriers 122 and loadlock 120. Any conventional robot type may be usedfor factory interface robot 126. Transfers may be carried out in anyorder or direction. Factory interface 106 may be maintained in, e.g., aslightly positive-pressure non-reactive gas environment (using, e.g.,nitrogen as the non-reactive gas).

The movement of transfer robot 112 and factory interface robot 126 andtransfer of substrates 102 within and/or between process chambers 114,116, and 118; loadlock 120; factory interface 106; and substratecarriers 122 may be controlled by a motor drive system (not shown inFIG. 1), which may include a plurality of servo or stepper motors.

Electronic device manufacturing system 100 may also include a systemcontroller 128. System controller 128 may be coupled to each of theactive hardware components to control operation thereof. Systemcontroller 128 may include a programmable processor, a memory thatstores processor executable instructions/software programs/firmware,various support circuits, and input/output circuits. System controller128 may also be configured to permit entry and display of data,operating commands, and the like by a human operator.

Electronic device manufacturing system 100 may further include a motioncontroller 130, described in more detail below in connection with FIGS.3-5B. Motion controller 130 may include a programmable processor, amemory that stores processor executable instructions/softwareprograms/firmware, various support circuits, and input/output circuits.Motion controller 130 may operate in a closed-loop position controlsystem, which may be referred to as servo control system, to collect andprocess data from actuator (motion) equipment within electronic devicemanufacturing system 100 by using various devices that may be coupled toa network both internal and external to the actuator (motion) drives ofthe actuator (motion) equipment for high-level supervisory tasks beyondcommutation of a motor. Motion controller 130 may operate independentlyof system controller 128, may provide information to system controller128, and/or may be controlled by system controller 128. Alternatively,system controller 128 may perform the functions of motion controller130, which may be omitted from electronic device manufacturing system100.

While process variability tolerance in the semiconductor industrycontinues to decrease as the size of semiconductor devices shrink, thereis a need to maintain a tightly controlled gap between processcomponents during substrate processing (e.g., deposition, annealing,curing, etching, and or other processing of a film on a substrate in aprocess chamber or loadlock).

Process components may include substrate support and process deliveryapparatus. Substrate support apparatus may include single or multi-axisactuators (e.g., motors) and may have single or multi-slot (two or morevertically) stacked substrates that may have lifts, elevators, orindexers to transport and support a substrate. Various embodiments ofprocess delivery apparatus may have actuators that may be used toposition process delivery assemblies (e.g., pattern masks and/or plasma,gas, or heat distribution assemblies) inside a process chamber orloadlock. Examples of such assemblies include cathode assemblies in etchprocess chambers or loadlocks, heater pedestal assemblies and gasdistribution showerhead assemblies in chemical vapor deposition andatomic layer deposition process chambers, and substrate pattern maskingassemblies in bevel etch process chambers or loadlocks. Bevel edgeetching may be used to remove undesirable portions of a deposition filmon an edge region of a substrate.

In accordance with one or more embodiments, FIGS. 2A-2E illustratevarious configurations of substrate support and process deliveryapparatus in a process chamber or loadlock, which may be similar oridentical to one or more of process chambers 114, 116, and/or 118,and/or loadlock 120.

FIG. 2A illustrates a process chamber or loadlock 214A that includes aprocess apparatus motor 232A configured to move process deliveryapparatus 233A vertically downward during a gap calibration such that abottom surface of process delivery apparatus 233A directly contacts atop surface of substrate 202A or substrate support 203A (e.g., in thosecases where substrate 202A is not yet received on substrate support203A).

FIG. 2B illustrates a process chamber or loadlock 214B that includes asubstrate support motor 234B configured to move substrate support 203Bvertically upward during a gap calibration such that a top surface ofsubstrate 202B or substrate support 203B (e.g., in those cases wheresubstrate 202B is not yet received on substrate support 203B) directlycontacts a bottom surface of process delivery apparatus 233B.

FIG. 2C illustrates a process chamber or loadlock 214C that includesboth a process apparatus motor 232C configured to move process deliveryapparatus 233C vertically downward and a substrate support motor 234Cconfigured to move substrate support 203C vertically upward such thatdirect contact occurs during a gap calibration between a bottom surfaceof process delivery apparatus 233C and a top surface of substrate 202Cor substrate support 203C (e.g., in those cases where substrate 202C isnot yet received on substrate support 203C).

FIG. 2D illustrates a substrate support 203D (with chamber not shown)having a pocket 205D for receiving a substrate 202D therein. A substratesupport motor 234D is configured to move substrate support 203Dvertically upward such that during a gap calibration direct contactoccurs between top substrate support surfaces 207D and a bottom surfaceof process delivery apparatus, such as, e.g., process delivery apparatus233A, 233B, and/or 233C, even though substrate 202D is received onsubstrate support 203D.

And FIG. 2E (with chamber not shown) illustrates a substrate supportmotor 234E configured to move substrate support 203E vertically upward,wherein substrate support 203E has pins or shafts 209E for supporting asubstrate 202E, such that during a gap calibration direct contact occursbetween a top surface of substrate 202E and a bottom surface of processdelivery apparatus, such as, e.g., process delivery apparatus 233A,233B, and/or 233C.

The moving process components shown in FIGS. 2A-2E may include actuatorswith large torque drive trains. Such large torque drive trains may beused to transport and/or support a substrate in order to provide a rigidand stable platform for the substrate that results in a consistentlyplanar surface with minimum vibration. Such rigid process components mayhave large wall thicknesses and may be constructed of materialsresistant to deformation, such as, e.g., steel or ceramic. The largewall thicknesses and the deformation resistant materials may contributeto a larger moving mass. These process components may also providemultiple functions including, e.g., heating, cooling, and mechanicallyor electrostatically chucking a substrate, and thus may include a largenumber of nested sub-components that may include heating, cooling,substrate chucking, and gas distribution elements. Furthermore, asubstrate may be continuously under vacuum in a process chamber, and toisolate the vacuum environment from atmosphere, a vacuum isolationelement such as a bellow may be included with these process components.As such, large pressure forces may develop across these vacuum isolationinterfaces when large diameter vacuum isolation elements are employedfor enclosing actuator shafts that bridge the actuator to the load invacuum. The diameter of the actuator shaft should be of sufficientinternal diameter to accommodate supply and return channels for fluid,gas, and electrical power. Axial forces may develop at vacuum isolationinterfaces that may be proportional to the diameter of the vacuumisolation element. Thus, such process components may have significantpayloads that require large torque high-efficiency ball screwdrivetrains that consequently have the capability of damaging (e.g.,crushing) some process components.

Supplementary feedback devices may also be embedded in a process chamberfor real time gap measurement and control in accordance with one or moreembodiments. These feedback devices may be a direct-contact ornon-contact type and may include, e.g., optical sensors, capacitivesensors, inductive sensors, and/or CCD (charge coupled device) cameras.Practical limitations of embedding sensors in process chambers orloadlocks may include the exposure of fragile sensor packaging andelectronics to elevated process temperature and strong chemicalreactions, susceptibility of electronics to high frequency electricaland plasma noise from the process chamber, and added mechanicalcomplexity from having to maintain vacuum integrity when packaging thesensor and routing signals in tight spaces.

Motion control systems and methods in accordance with one or moreembodiments advantageously provide completely closed-chamber and in-situsubstrate gap calibration at process pressures (ranging from, e.g., 0.01Torr to about 80 Torr) and/or at process temperatures (ranging from,e.g., 100 degrees C. to 700 degrees C.). Thus, a process chamber orloadlock may need not to be taken offline for typically very manuallyinvolved maintenance procedures in order to perform gap calibration. Themotion control systems and methods of the disclosure may alsoadvantageously eliminate the need for specialized and supplementalsensors, products, and/or tools for gap measurement and calibration. Themotion control systems and methods of the disclosure may furtheradvantageously not require additional mechanical or electricalcomplexity wherein, in some embodiments, actuator feedback signals maybe directly used. The motion control systems and methods of thedisclosure may still further advantageously combine the principles ofgain scheduling, distributed motion planning, and signal processing toroutinely confirm and maintain accurate gap control at the center of theprocess using a primary actuator's feedback. The motion control systemsand methods of the disclosure may be less sensitive to a processingenvironment and may account for the actual dimension altering effects ofthermal expansion (caused by high process temperatures) on gap spacing,thereby increasing the accuracy of gap calibration and control.

Motion control systems and methods in accordance with one or moreembodiments advantageously may overcome a number of practicallimitations, which may include (1) large torque actuators capable ofexceeding the allowable stress limits of structural components inside aprocess chamber, (2) gross mechanical flexure of structural componentsof a process chamber or loadlock, (3) distributed motion networkbandwidth limitations imposed on motion control signals and motionfeedback signals, and (4) noise in motion feedback signals.

FIG. 3 illustrates a motion control system 300 that may be used in anelectronic device manufacturing system, such as, e.g., electronic devicemanufacturing system 100. Motion control system 300 may be used tocontrol movements within a process chamber or loadlock 314 of processdelivery apparatus 333 (which may be, e.g., identical or similar toprocess delivery apparatus 233A or 233C of FIG. 2) and/or a substratesupport 303 (which may be, e.g., identical or similar to substratesupports 203B-E of FIG. 2) in accordance with one or more embodiments.Process chamber or loadlock 314 may be evacuated uniformly by a vacuumpump (not shown). Substrate support 303 may be centrally disposed inprocess chamber or loadlock 314 and, in some embodiments, substratesupport 303 may include at least one embedded heater, which may beoperable to controllably heat substrate support 303 and a substrate 302received thereon to a predetermined temperature.

Motion control system 300 may include a motion controller 330, which maybe identical or similar to motion controller 130 of FIG. 1. Motioncontrol system 300 may also include one or more actuators 332 and 334, acommunications network 336 coupled to motion controller 330, one or moreactuator drivers 338A and 338B each coupled to communications network336, and one or more feedback devices 340A and 340B. Feedback devices340A and 340B may each be, e.g., a position sensor and/or other suitablesensor device(s) configured to sense, e.g., velocity, torque, current,force, and/or strain. Depending on the configuration of substratesupport 303 and process delivery apparatus 333, actuators 332 and 334may be one or more of, e.g., a process apparatus motor and/or asubstrate support motor, such as, e.g., process apparatus motors 232Aand/or 232C and/or substrate support motors 234B-E. Process deliveryapparatus 333 may include a pattern mask and/or a plasma or gasdistribution assembly.

In some embodiments, actuator 332 may be a multidirectional movementdevice configured to move and position process delivery apparatus 333relative to substrate 302. Actuator 332 may be part of an electricalmotor-based system, which can be used to adjust the position of processdelivery apparatus 333 along all three axes (X-Y-Z). In someembodiments, actuator 332 may include a mechanical fixture in connectionwith an electric motor that can move process delivery apparatus 333 in afirst direction. The electric motor via a second fixture, such as astainless steel ring, may then move process delivery apparatus 333 in asecond direction and a third direction. Thus, by pivoting processdelivery apparatus 333 while moving process delivery apparatus 333 upand down, process delivery apparatus 333 may be repositioned along allthree axes. Furthermore, actuator 332 may level process deliveryapparatus 333 relative to substrate support 303.

A system controller 328, which may be a system controller of anelectronic device manufacturing system, such as, e.g., system controller128 of FIG. 1, may communicate with motion controller 330 and/oractuator drivers 338A and 338B via communications network 336 or,alternatively, via a dedicated communication channel 337 coupleddirectly to motion controller 330. Alternatively, system controller 328may perform the functions of motion controller 330, which may beomitted.

Actuator driver 338A may communicate with and control correspondingactuator 332 and feedback device 340B, and actuator driver 338B maycommunicate with and control corresponding actuator 334 and feedbackdevice 340B. Actuator drivers 338A and 338B are each configured toprovide controlled motion of respective actuators 332 and 334 andthereby control respective movement of process delivery apparatus 333and/or substrate support 303. Actuator drivers 338A and 338B may eachinclude programmable processing capability configured to executeprogrammable instructions/software programs/firmware that may include,e.g., a position feedback loop, a velocity feedback loop, and a motionplanner, as described in more detail below in connection with FIGS. 4and 5A-B.

Motion controller 330 may include a programmable processor and a memorythat stores processor executable instructions/software programs/firmwareand data received from actuator drivers 338A and 338B and feedbackdevices 340A and 340B. Motion controller 330 may also include varioussupport circuits (e.g., for a power supply and network communications)and input/output circuits. In some embodiments, motion controller 330may include executable instructions/software programs/firmware havingsignal processing capability stored in its memory and executable by itsprogrammable processor. In addition to actuator drivers 338A and 338B,motion controller 330 may also be coupled via communications network 336to one or more other remote devices 342, which may be, e.g., one or moreI/O modules providing, e.g., signals based on position, alignment, orother status of one or more process components.

Motion controller 330 may communicate over communications network 336using, e.g., the CANopen (Controller Area Network open) communicationprotocol. The CANopen protocol is based on a master-slave communicationmodel. As such, motion controller 330 may be the CANopen node designatedas the master, which sends and requests data to and from the slaves,which may be actuator drivers 338A and 338B and any other remote devices342 designated as slaves. Using this communication model, the master isable to start, stop, and reset the slaves, among other commands. Inaccordance with one or more embodiments, motion controller 330 (themaster) may execute all instructions and transmit all commands overcommunications network 336 to actuator drivers 338A and 338B, which maybe referred to as remote nodes (slaves). In some embodiments,communications network 336 may operate at a sampling rate greater thanabout 50 Hz and less than about 1000 Hz. An example motion instruction,when executed by one or both of actuator drivers 338A and 338B, mayinitiate movement of one or both of actuators 332 and 334 between afirst position and a second position within predefined constraints ofvelocity and acceleration.

FIG. 4 illustrates a method 400 of calibrating a gap between processcomponents in a process chamber or loadlock of an electronic devicemanufacturing system, such as electronic device manufacturing system100, without taking the process chamber or loadlock offline inaccordance with one or more embodiments. Method 400 may be performed bya motion controller, such as, e.g., motion controller 130 (of FIG. 1) ormotion controller 330 (of FIG. 3) in any one of process chambers 114,116, 118 and loadlock 120 of FIG. 1, process chambers or loadlocks214A-C of FIG. 2, process chamber or loadlock 314 of FIG. 3, and anyother chamber where substrate processing may occur. Method 400 maycalibrate a gap such as a gap G1 (see FIG. 3) between process deliveryapparatus 333 and substrate 302, and/or a gap G2 between processdelivery apparatus 333 and substrate support 303 (in those cases wheresubstrate 302 has not yet been received on substrate support 303).

A software control program, e.g., executing in the motion controller(master) may identify the software/firmware executing in one or moreactuator drivers (slaves), such as, e.g., actuator drivers 338A and 338Bof FIG. 3, and may transmit instructions over a communication network,such as, e.g., communication network 336, to the actuator drivers. Uponreceiving instructions and upon completing instructions, the actuatordrivers communicate with the motion controller (master) to indicatecompletion. Subsequent instructions are dependent on prior instructionshaving successfully completed in the actuator drivers.

Distributed motion networks in accordance with one or more embodimentsmay permit distributed motion planning while providing closecoordination with instructions from the motion controller (master).Software programs/firmware may be stored respectively in the motioncontroller (master) and in the actuator drivers (slave). This may allowmotion planning to be distributed among the master and slave(s) andreduces the burden on the master and the communication network byreducing the amount of data transfer that may occur over thecommunication network. For example, a motion instruction with respect togap calibration generated by the motion controller (master) may initiatemovement of an actuator (e.g., a motor) between a first position (e.g.,a safe starting position) and a second position (e.g., a target positionbeyond the expected contact position) within predefined constraints ofvelocity and acceleration. The motion instruction may be received by amotion planner internal to an actuator driver (slave) which, based onthe motion instruction data, generates a motion profile preciselydescribing the motion of the actuator (e.g., motor) on an instant byinstant basis to control speed and acceleration changes, e.g., to limit“jerk,” the first derivative of acceleration, the latter which mayproduce undesired wear or oscillations on the motor and attachedcomponents.

Accordingly, the commanded motion data need not be transmitted over thecommunication network, but only the higher-level motion command thatinitiates the motion planner in the actuator drivers. The distributednature of motion planning frees up communication network traffic fortransmitting real-time process data including motion feedback data(which may be between one sample per millisecond and one sample per 20milliseconds) from the actuator drivers to the motion controller withoutreducing motion positioning performance. As will become apparent, thisalso allows the motion controller (master) to control multiple actuatordrivers (slaves) concurrently for gap calibration or other functions.Method 400 may therefore be performed in a motion control system havingmotion-planning capable actuator drivers in accordance with one or moreembodiments.

At process block 402, method 400 may begin by preparing for a gapcalibration by issuing preparatory instructions from the motioncontroller (master) to the one or more actuator drivers (slaves). Thismay include opening or establishing communication between the motioncontroller (master) and the one or more actuator drivers (slaves). Thenumber of actuator drivers depends on the process componentconfiguration (see, e.g., FIGS. 2A-E). In particular, process block 402may include issuing one or more of the following preparatoryinstructions from the motion controller (master) to configure and/oroperate the one or more actuator drivers (slaves):

(1) Set the mode of operation in the one or more actuator drivers toallow the one or more actuator drivers to generate (or plan) theappropriate motion profile internally. For example, the actuator drivermay provide a position control mode of operation in which a trapezoidalposition profile is generated internally by the motion planner in theactuator driver within predefined constraints on velocity andacceleration.

(2) Command one or more actuators, such as, e.g., actuators 332 and/or334, to move to a safe starting position from an expected contactposition between two pre-defined surfaces, such as, e.g., a top surfaceof substrate 302 and a bottom surface of process delivery apparatus 333.

(3) Disable relevant fault protections in the one or more actuatordrivers including position tracking error such that the gap calibrationprocess does not prematurely fault-out.

(4) Set (or schedule) position loop and velocity loop feedback gains(which may be referred to as PID gains) in the one or more actuatordrivers to reduce a low frequency actuator (e.g., motor) response (i.e.,the rate at which an actuator (e.g., motor) current (torque) responds tovery-slow time-varying disturbance such as a direct contactobstruction).

(5) Set (or schedule) commanded velocity to a very low actuator shaftfrequency (which may be less than one rpm; when the gap calibrationmotion is triggered to start, the actuator shaft frequency may be lowenough that when combined with the elimination of integral action onactuator current, the actuator current may not respond rapidly toobstructed motion at direct contact of the process components and thismay greatly reduce the contact forces on those components).

(6) Set (or schedule) the commanded position to a target position thatexceeds the expected contact position to ensure that contact betweenprocess component surfaces does occur.

Regarding preparatory instruction (4), in one or more embodiments asshown in FIGS. 5A and 5B, the position and velocity loops in theactuator drives may be in a cascaded form. FIG. 5A depicts a generalcontrol system divided into the “plant” and the controller. A goal ofthis control system is to drive the plant in response to the command(ycmd) while overcoming disturbances. The plant includes a feedbackdevice and the element or elements that produce the system response. Forexample, the plant may be a motor coupled to its load with a feedbackdevice attached to the motor, the load, or to both. The plant receivesthe controller output (u) from the power converter (not shown) and sendsthe feedback signal (y) to the controller. The controller can be dividedinto the cascaded position and velocity loops. The position loopcontains the position proportional gain (Ppos) and receives the errorsignal (e) that is the difference between commanded position (ycmd) andthe feedback signal (y). The velocity loop contains the velocityproportional gain (Peel) and the velocity integral gain (Ivel). Thevelocity loop receives the sum of the signals that includes the outputof the position loop, the derivative of the commanded position(commanded velocity), and the derivative of the feedback signal. Theterm s represents a differentiation operation on the signal and the term1/s represents an integration operation on the signal. Similarly, FIG.5B depicts a general control system divided into the plant and thecontroller. The controller in this case consists of a single loop andcontains the proportional gain (P), integral gain (I), and thederivative gain (D). According to PID theory, each of the control termswithin the controller shown in FIGS. 5A and 5B are dominant in one oflow, middle, or high frequency zones of an actuator current response. Bysetting the terms that provide integral action upon the actuatorcurrent, the rate at which the actuator current (torque) responds tovery-slowly time-varying disturbances can be effectively slowed. In someembodiments, this may be accomplished by sending instructions from themotion controller (master) to the one or more actuator drivers to setthe “Ivel” term in FIG. 5A and the “I” term in FIG. 5B to zero.

At process block 404, method 400 may include actuating the one or moreactuators in the process chamber or loadlock to cause direct contactbetween process component surfaces without taking the process chamber orloadlock offline. In particular, process block 404 may include themotion controller (master) performing the following:

(1) Polling (i.e., collecting) on a continuous basis and charting a timeseries of process data from one or more feedback devices, such as, e.g.,feedback devices 340A and/or 340B. This process feedback may includeposition, position error, actuator (e.g., motor) current, actuator(e.g., motor) velocity, strain, force, or other signals available on thecommunication network. The sampling rate may be the maximum allowed onthe communication network (which may range from about one sample permillisecond to one sample per 20 milliseconds).

(2) Filtering digitally (i.e., removing) via the software controlprogram executing in the motion controller stochastic (random) noise anddeterministic (periodic) noise from actuator (e.g., motor) feedback.Actuators used in process chambers and loadlocks herein may have lowfrequency mechanical resonance caused by one or more of the following:compliance between a motor and a load, misalignment of bearing and motoraxis, eccentricity of rotating components, and/or pulsating torqueripples from motor cogging at low velocities. Low pass, band pass, andnotch pass filters may each be used to filter undesired frequenciesconsidered noise. Filtering is used to improve the signal-to-noise ratiosuch that the software control program executing in the motioncontroller may more clearly and more rapidly discern and respond to thedirect contact between process component surfaces.

(3) Estimating actuator feedback via the software control programexecuting in the motion controller using a circular moving averagefilter to fit the actual feedback signal. By creating a sufficientlylarge signal buffer in the motion controller's memory that is equivalentto at least one actuator (e.g., motor) revolution, the software controlprogram executing in the motion controller may create a derivedestimated feedback signal and a second derived residual signal, whichmay be the difference between the estimated and actual feedback.

(4) Detecting direct contact between the surfaces of process deliveryapparatus and a substrate or a substrate support. In real-time with theactuator in motion, the estimated and actual signals may deviate sharplyat the point of direct contact between the surfaces of process deliveryapparatus and a substrate or a substrate support. When obstructed motionis encountered, the estimated motor feedback may not deviate whereas theactual feedback may deviate rapidly. In turn, the residual signal mayrise or drop very rapidly and the software control program executing inthe motion controller may thus detect direct contact inside the processchamber or loadlock sufficiently accurately and rapidly.

At process block 406, method 400 may include responding to detecteddirect contact between component surfaces, such as, e.g., the surfacesof process delivery apparatus and a substrate or a substrate support ina process chamber or loadlock. In particular, process block 406 mayinclude the motion controller executing the software control program toissue instructions to halt the motion driven by the one or moreactuators and to record the calibration positions of the one or moreactuators into the memory of the motion controller. The calibrationpositions may include the actual actuator position at the contactposition and at a defined mechanical gap spacing (e.g., as small as 1mil). Process block 406 may also include the software control programissuing instructions to restore the mode of operation in the one or moreactuator drivers to a normal operating mode.

The foregoing description discloses only example embodiments of thedisclosure. Modifications of the above-disclosed apparatus, systems, andmethods may fall within the scope of the disclosure. Accordingly, whileexample embodiments of the disclosure have been disclosed, it should beunderstood that other embodiments may fall within the scope of thedisclosure, as defined by the following claims.

What is claimed is:
 1. A motion control system of an electronic devicemanufacturing system comprising: a motion controller comprising aprogrammable processor, a memory, and a gap calibration software programstored in the memory and executable by the programmable processor; anactuator driver coupled to the motion controller and comprising a driversoftware program; an actuator coupled to the actuator driver and to aprocess delivery apparatus or a substrate support located in a processchamber or loadlock, the actuator configured to move the processdelivery apparatus or the substrate support; and a feedback devicecoupled to the actuator and to the motion controller; wherein: the gapcalibration software program is configured to cause direct contactbetween respective surfaces of the process delivery apparatus and thesubstrate support or a substrate received on the substrate support. 2.The motion control system of claim 1, wherein the motion controller, theactuator driver, the actuator, and the feedback device are operablewhile the process chamber or loadlock is at a process temperature or aprocess pressure during execution of the gap calibration softwareprogram.
 3. The motion control system of claim 2, wherein the processtemperature ranges from 100 degrees C. to 700 degrees C. and the processpressure ranges from 0.01 Torr to about 80 Torr.
 4. The motion controlsystem of claim 1, wherein the driver software program comprises atleast one of signal processing capability, a position feedback loop, avelocity feedback loop, or a motion planner.
 5. The motion controlsystem of claim 1, wherein the gap calibration software programcomprises signal processing capability, a motion planner, or both. 6.The motion control system of claim 1, further comprising a communicationnetwork coupled to the motion controller, the actuator driver, theactuator, and the feedback device, the communication network using aCANopen communication protocol.
 7. The motion control system of claim 1,wherein the feedback device measures at least one of position, velocity,torque, current, force, or strain.
 8. The motion control system of claim1, wherein: the actuator driver comprises a plurality of actuatordrivers; the actuator comprises a plurality of actuators; and thefeedback device comprises a plurality of feedback devices; wherein: thepluralities of actuator drivers, actuators, and feedback devices areconcurrently operated by the motion controller during execution of thegap calibration software program.
 9. An electronic device manufacturingsystem, comprising: a transfer chamber; a process chamber coupled to thetransfer chamber, the transfer chamber configured to transfer one ormore substrates to and from the process chamber, the process chamberconfigured to process the one or more substrates therein; a loadlockcoupled to the transfer chamber, the transfer chamber configured totransfer the one or more substrates to and from the loadlock; and amotion controller comprising a programmable processor, a memory, and agap calibration software program stored in the memory and executable bythe programmable processor, the gap calibration software programconfigured to cause direct contact within the process chamber betweenrespective surfaces of process delivery apparatus and a substratesupport or one of the one or more substrates received on the substratesupport.
 10. The electronic device manufacturing system of claim 9,wherein the loadlock is configured to process one or more of the one ormore substrates therein.
 11. The electronic device manufacturing systemof claim 10, wherein the gap calibration software program is furtherconfigured to cause direct contact within the loadlock betweenrespective surfaces of loadlock process delivery apparatus and aloadlock substrate support or one of the one or more substrates receivedon the loadlock substrate support.
 12. The electronic devicemanufacturing system of claim 9, wherein the process chamber or theloadlock is at a process temperature or a process pressure duringexecution of the gap calibration software program.
 13. The electronicdevice manufacturing system of claim 9, further comprising: an actuatordriver coupled to the motion controller and comprising a driver softwareprogram; an actuator coupled to the actuator driver and to the processdelivery apparatus or the substrate support located in the processchamber, the actuator configured to move the process delivery apparatusor the substrate support; and a feedback device coupled to the actuatorand to the motion controller.
 14. A method of calibrating a gap betweencomponent surfaces in a process chamber or a loadlock of an electronicdevice manufacturing system, the method comprising: preparing for a gapcalibration by issuing preparatory instructions from a motion controllerto one or more actuator drivers; actuating one or more actuators in theprocess chamber or the loadlock to cause direct contact between thecomponent surfaces without taking the process chamber or the loadlockoffline; and responding to detected direct contact between the componentsurfaces.
 15. The method of claim 14, wherein the preparing comprises:setting a mode of operation in the one or more actuator drivers to a gapcalibration mode to allow the one or more actuator drivers to generate amotion profile; commanding the one or more actuators to move to a safestarting position; disabling fault protections in the one or moreactuator drivers to prevent a premature fault-out; setting position loopand velocity loop feedback gains; setting a commanded velocity to a lowshaft frequency; and setting a commanded position to a target positionthat exceeds an expected contact position to ensure that direct contactbetween the component surfaces occurs.
 16. The method of claim 14,wherein the actuating comprises: polling and charting a time series ofprocess data from one or more feedback devices; filtering digitally viaa software control program executing in the motion controller stochasticnoise and deterministic noise from actuator feedback; estimating theactuator feedback via the software control program executing in themotion controller using a circular moving average filter to fit anactual feedback signal; and detecting direct contact between thecomponent surfaces.
 17. The method of claim 14, wherein the respondingcomprises: halting motion of the one or more actuators; storingcalibration positions of the one or more actuators into a memory of themotion controller; and restoring a mode of operation in the one or moreactuator drivers to a normal operating mode.
 18. The method of claim 14,wherein the component surfaces comprise surfaces of process deliveryapparatus and a substrate or a substrate support.
 19. The method ofclaim 14, wherein the preparing, actuating, and responding are performedwhile maintaining the process chamber or loadlock at a processtemperature or a process pressure.
 20. The method of claim 14, whereinthe process temperature ranges from 100 degrees C. to 700 degrees C. andthe process pressure ranges from 0.01 Torr to about 80 Torr.